Answer:
6. 5
7.2
8.6
9.-12
Step-by-step explanation:
Answer:C. (77.29, 85.71)
Step-by-step explanation:
We want to determine a 95% confidence interval for the mean test score of randomly selected students.
Number of sample, n = 25
Mean, u = 81.5
Standard deviation, s = 10.2
For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean +/- z ×standard deviation/√n
It becomes
81.5 +/- 1.96 × 10.2/√25
= 81.5 +/- 1.96 × 2.04
= 81.5 +/- 3.9984
The lower end of the confidence interval is 81.5 - 3.9984 =77.5016
The upper end of the confidence interval is 81.5 + 3.9984 =85.4984
Therefore, the correct option is
C. (77.29, 85.71)
Answer:
Yes , those ratios are equivalent, because if you simply 18:8 inti the smpilest form you'll get 9:4.
Step-by-step explanation:
18:8= 18/8
18/8÷2/2=9/4
Answer:
B
Step-by-step explanation:
